To know thyself is the beginning of wisdom.

I am quite ready to acknowledge . . . that I ought to be grieved at death, if I were not persuaded that I am going to other gods who are wise and good (of this I am as certain as I can be of any such matters), and to men departed who are better than those whom I leave behind. And therefore I do not grieve as I might have done, for I have good hope that there is yet something remaining for the dead.

The right way to begin is to pay attention to the young, and make them just as good as possible.

It is possible that a man could live twice as long if he didn't spend the first half of his life acquiring habits that shortens the other half

To know, is to know that you know nothing. That is the meaning of true knowledge. For a man who claims to have knowledge, while actually knowing nothing, is less smarter than you, who claim to know nothing.

Knowing thyself is the height of wisdom.

The bad one is that way because of the ignorance, therefore he can be healed with wisdom.